This description relates to flow controllers.
A flow controller regulates the flow rate of a fluid from a source, e.g., a fluid pump, to a final receiving point, e.g., a patient, through one or more fluid-carrying channels, e.g., silicone-based tubes. In the context of a patient receiving medication, a flow controller allows for adjustment of the dose of medication as deemed appropriate during therapy. Flow controllers have been used in conjunction with fluid pumps that have fixed rates of flow output.
Typically, flow controllers operate on the concept that flow rates of a fluid through a fluid-carrying channel vary according to the diameter of a lumen of the channel, or according to a length of the channel, if other factors such as temperature and viscosity remain constant. This is based on Bernoulli's Principle. Conventional flow controllers achieve different flow rates by pinching off (e.g., clamping, pressing or occluding) one or more fluid-carrying channels using a teeth/groove or plunger (spring and non-spring loaded) mechanism, or by selectively opening and closing one or more fluid-carrying channels using a cam mechanism. Over time, such mechanical mechanisms have led to reduced structural integrity of the fluid-carrying channels even though pliable materials such as silicone tubes are used to reduce memory related issues. Such mechanical mechanisms have also employed leak-prone complex couplings to connect the desired fluid-carrying channel(s) to a distal end of the flow. In addition, flow controllers have not been easily portable due to complexity and size.